Device for applying a helical spring connector to a plurality of wires or rods

ABSTRACT

A HELICAL SPRING CONNECTOR HAS LONGITUDINALLY SPACED ENDS AND A SERIES OF INTERMEDIATE RESILIENT CONVOLUTIONS, THE SPACED ENDS PROJECTING OUTWARDLY. THE DEVICE FOR APPLYING SUCH A CONNECTOR TO A PLURALITY OF WIRES OR RODS INCLUDES A TUBULAR MEMBER THROUGH WHICH THE CONNECTOR IS ADVANCED, THE FORWARD END OF THE CONNECTOR BEING ANGULARLY SHIFTED BY CAM ACTION WITH RESPECT TO THE TRAILING OR REAR END AS THE ADVANCEMENT PROGRESSES. SUCH ACTION TRANSVERSELY ENLARGES THE CONVOLUTIONS FOR THE RECEPTION OF THE ROD-LIKE ELEMENTS. WHEN THE FORWARD END REACHES THE END OF THE TUBULAR MEMBER, IT IS RELEASED AND SNAPS BACK TO ITS NORMAL POSITION, THE ENLARGED CONVOLUTIONS CONTRACTING AGAINST THE INSERTED ELEMENTS. A FEEDING MECHANISM IS PROVIDED FOR ADVANCING A NUMBER OF CONNECTORS IN SUCCESSION THROUGH THE TUBULAR MEMBER.

March 1971 J. H. BLOMSTRAND I 3,570,102

DEVICE FOR APPLYING A HELICAL SPRING CONNECTOR TO A PLURALITY 0F WIRES 0R RODS Filed Feb. 17, 1969 2 Sheets-Sheet l FIE! .257

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2 c 2/54 I206 l2 0d 6 4 INVENTOR. J'amv 1/. azonsrznup lrrazmrys United States Patent Office US. 'Cl. 29212 12 Claims ABSTRACT OF THE DISCLOSURE A helical spring connector has longitudinally spaced ends and a series of intermediate resilient convolutions, the spaced ends projecting outwardly. The device for applying such a connector to a plurality of Wires or rods includes a tubular member through which the connector is advanced, the forward end of the connector being angularly shifted by cam action with respect to the trailing or rear end as the advancement progresses. Such action transversely enlarges the convolutions for the reception of the rod-like elements. When the forward end reaches the end of the tubular member, it is released and snaps back to its normal position, the enlarged convolutions contracting against the inserted elements. A feeding mechanism is provided for advancing a number of connectors in succession through the tubular member.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates generally to helical spring connectors, and pertains more articularly to a device for applying such connectors to a pair of rod-like elements.

(2) Description of the prior art A number of devices, such as the wire connector depicted in my US. Pat. No. 2,656,204, have been employed for the purpose of connecting wires together. These prior art devices have required a manual twisting of the connector in order to effect the desired connection of the wires that are to be joined together. Thus, while the prior art devices, particularly when used for connecting electrical wires together, have obviated the need for resorting to solder, such devices have required a certain amount of effort and care on the part of the user in effecting the connection. Also, they have not adapted themselves readily to the joining of wires, particularly when associated with miniaturized electronic components or conductors located in relatively inaccessible environments where the twisting action cannot easily be accomplished.

SUMMARY OF THE INVENTION One object of the present invention is to utilize a helical spring connector for joining together a plurality of wires or rods, doing so with a simple device that angularly displaces one end of the helical spring connector with respect to the other as the connector is advanced through a passage formed in the member constituting the device.

Another object of the invention is to obviate any need for twisting the connector with respect to the rod-like elements to be joined.

A further object is to provide a device for effecting the connection of wires or rods together that can be used where miniaturization is necessary or highly desirable. In this regard, an aim of the invention is to provide a simple device that will find especial utility in the electronics field for connecting together electrical conductors or other elements that are of small diameter and which are too flexible to permit the twisting of a conventional wire nut thereon.

Patented Mar. 16, 1971 Yet another object is to provide a device for applying helical spring connectors to rod-like elements which can be manufactured at a relatively low cost.

Still another object of the invention is to provide a device of the foregoing character in which a group of connectors will be successively fed into position so that they are in immediate readiness for the next production line fastening operation. Thus, my invention will be of particular value where a number of identical connectors are to be applied, the invention enabling the operator to efficiently apply such connectors in rapid sequence.

Briefly, my invention comprises a tubular member having a bore extending therethrough, the helical spring connector being inserted into the bore at one end. By means of groove means extending outwardly from the bore, the ends of the helical spring connector are flexed or angularly shifted with respect to each other in a direction to cause the expansion or enlargement of the resilient convolutions. The enlargement takes place automatically as the connector is advanced from one end of the tubular member to the other. When the forward end of the connector reaches the end of the bore it becomes free to rotate and the enlarged convolutions immediately contract so as to grip and hold the wires or rods that are inserted during the period that the convolutions are transversely enlarged. A gun-like device feeds the individual connectors in sequence. It is within the purview of the invention to glue or adhere the various connectors in a columnar form to facilitate their loading into the gun.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of a gun for feeding in sequence various individual helical spring connectors so as to cause enlargement of their respective convolutions;

FIG. 2 is a perspective view of a single helical spring connector, the view exemplifying one form the connector may take when practicing the invention;

FIG. 3 is a fragmentary enlarged sectional view of the barrel depicted in FIG 1, but with the helical spring connectors removed so as to illustrate the single camming groove that causes the transverse enlargement of the resilient convolutions;

FIG. 4 is a sectional view taken in the direction of line 44 of FIG. 3, the view being taken in the region of the wide end of the camming groove and also illustrating in phantom outline the configuration that the helical spring connector assumes at this location;

FIG. 5 is an end view of the helical spring connector of FIG. 2 as it would appear when at the location depicted in FIG. 4;

. FIG. 6 is a sectional view taken in the direction of line 6-6 of FIG. 3 to show the reduced width of the groove as compared with FIG. 4 and the deflection that occurs at this stage of the ends of the helical spring connector, the connector once again being shown in phantom outline;

FIG. 7 is an end view of the connector corresponding to the phantom position illustrated in FIG 6;

FIG. 8 is a sectional view taken in the direction of line 8-8 of FIG. 3, the view illustrating the narrow end of camming groove with the phantom outline of the connector illustrating the extent to which the ends of the connector have been angularly shifted at this final stage of deflection;

FIG. 9 is an end view of the helical spring connector as it reaches the region designated in FIG. 8 the view representing the helical spring connector just prior to the release of the forward end of the connector from the camming groove;

FIG. 10 is an end view of the helical spring connector after it has been expelled from the barrel shown in FIGS. 1 and 3, the helical spring connector gripping the pair of wires or rods that have been inserted as illustrated in FIG. 1;

FIG. 11 is a perspective view of a modfied helical spring connector that may be used in the practicing of the invention;

FIG. 12 is a sectional view corresponding to FIG. 3 but depicting a barrel with a groove arrangement differing from that pictured in FIG. 3 so as to accommodate the type of connector appearing in FIG. 11;

FIGS. 13-18 correspond respectively to FIGS. 49, but with the barrel of FIG. 12 acting on the connector of FIG. 11, and

FIG. 19 is an end view of the helical spring connector depicted in FIG. 11 with the connector gripping the wires or rods in the same manner as the Wires or rods are gripped in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, a pair of wires or rods have been indicated by the reference numerals and 12. It will be appreciated that the term Wires will be embracive of various types of electrical conductors, whereas the term rods will be embracive of studs, baling wire and other elements, or a combination thereof, that are to be gripped and held.

FIG. 2 depicts a helical spring connector designated generally by the reference numeral 14, a number of such connectors appearing in FIG. 1. The connector 14 is formed with longitudinally spaced, tangentially projecting first and second ends '16 and 18 and also has a series of intermediate resilient convolutions 20 that are transversely enlarged in a manner hereinafter explained so as to receive therein the wires or rods 10 and 12 appearing in FIG. 1.

The device for enlarging the convolutions 20 as the connector 14 is advanced therethrough is exemplified in FIG. 1. It will be perceived that FIG. 1 depicts a gun indicated generally by the reference numeral 22 and comprises a tubular barrel 24 having a fiat end 26 residing in a plane perpendicular or normal to the longitudinal axis of the barrel, the end 26 being the location at which the various connectors 14 are expelled fromthe gun. The tubular barrel 24 has a cylindrical passage or bore 28 that has a cross section of sufiicient size so as to accommodate the various convolutions 20. The tubular barrel 24 also has a groove denoted generally by the reference numeral 30, the groove 30 having a wide end portion labeled 30a and a narrow end portion 3%, the narrow end portion 30b extending to the fiat end 26 of the barrel 24.

The groove 30 plays an important role in the practicing of the invention and will be described with considerable particularity. In this regard, the groove 30 has sides 32 and 34. At the extreme right in FIG. 3, the sides 32 and 34 are parallel with each other and form the wide end of the groove 30. As illustrated in FIGS. 3 and 4, however, the groove 30 starts to become narrower and the sides thereof have been labeled 32a and 34a. The groove 30 becomes more narrow when the plane in which FIG. 6 is taken is reached, the sides in this region having been designated as 32b and 34b. On the other hand, where the groove narrows to its fullest degree, this being adjacent the fiat end 26 of the barrel 24, the sides have been designated as 32c and 340. It will be appreciated that the sides 32c, 340 in providing the narrow end 30b of the groove 30 are parallel but are closer together than the parallel sides 32, 34 which form the wide end 30a.

More information will be given hereinafter concerning the functioning of the groove 30 with respect to the helical spring connector 14 as it passs or advances through the bore 28. At this time, though, attention is directed to the feed mechanism designated in its entirety by the reference numeral 36. From FIG. 1, it will be perceived that the feed mechanism 36 includes a pistol grip or stock 38. The stock 38 has a generally hollow interior but is proyided with a side opening 40. In the portion of the barrel 24 residing just above the stock 38 is a ratchet bar 42 having a cross section corresponding to that of the bore or passage 28. The ratchet bar 42 has a plurality of longitudinally spaced teeth 44 formed by intervening notches 46. The ratchet bar 42 is actuated or forced to the left in increments by virtue of a pawl 48 having a jaw 50 at one end and a rounded, but somewhat pointed, dog 52 at its other end.

Intermediate the ends of the pawl 48 is a pivot pin 54 carried at the upper end of a trigger 56, the trigger 56 being pivotal on a tranverse pin 58 extending through the sides of the stock 38. The trigger 56 is normally biased into its solid line position by means of a scar or hairpin spring 60 but the spring 60 readily yields when the trigger 56 is squeezed by the operator to cause the ratchet bar 42 to be advanced by corresponding to the length of one connector 14 one increment. A somewhat smaller sear or hairpin spring 62 biases the pawl 48 upwardly so as to normally effect engagement of its jaw 50 in one of the notches 46 so as to abut one of the teeth 44. The spring 62, as can be discerned from FIG. 1, has an outturned end bearing against the lower edge of the side opening 40 and has its other free end extending into a notch 64 formed on the underside of the pawl 48. To permit the biasing action of the spring 62 to be overcome is a release pin or knob 66 projecting laterally through the opening 40 so as to be accessible to the operator when he de sires to retract the ratchet bar 42. A detent in the form of a latch spring 68 is frictionally engageable with the dog 52 on the pawl 48, the spring 68 yielding to permit the dog 52 to pass upwardly and reside above the upper end of the spring 68.

Having presented the foregoing description, it will be helpful at this stage to give an operational account of what occurs when utilizing the connector 14 in the device 22. In this regard, the ratchet bar 42 is removed from the right end of the barrel 24 so that any preferred number of the connectors 14 can be inserted. A manual depressing of the pin or knob 66 permits this. When then placing the various connectors 14 into the bore or passage 28, the ends 16, 18 are caused to be received in the groove 30 at its wide end 30a, the wide portion extending to the right end of the barrel 24. With the end 16 of each connector 14 foremost, the connectors 14 are shifted or moved into a magazine or storage section within the barrel 24. Such a section having the legend magazine applied thereto in FIG. 1 and which section would extend from line 44 toward the right in FIG. 3.

When loaded as described above, the gun 22 is in readines for use. All that the operator need do is squeeze the trigger 56 and the pawl 48 is moved from its solid position in FIG. 1 to its dotted outline position. It will be appreciated that the spacing of the notches 46 and the various teeth 44 is such that a full squeezing of the trigger 56 will cause the jaw 50 of the pawl to advance through a distance corresponding to the length of each connector 14 to constitute one increment as hereinbefore mentioned.

Hence, as the connectors 14 are incrementally advanced by the ratchet rod 42, the ends 16 and 18 are forced angularly by the sides 32, 34 of the groove 30 in a direction so that they become progressively more in a longitudinal alignment with each other. Consequently, when the ends 16, 18 reach the vicinity of the barrel 24 represented by FIG. 4, the sides 32, 34 of the groove 30 begin to converge and have at this location been assigned the designations 32a, 34a. These sides form camming surfaces that continually fiex the ends toward alignment with each other. FIG. 5 depicts the ends as they are just beginning to be cammed by the sides 32a, 34a.

As a given connector 14 moves farther to the left, it reaches the section of the barrel 24 illustrated in FIG. 6. Here, as can readily be seen, the groove 30 is narrower. The relationship of the ends of the connector 14 have been indicated by the reference numerals 16b and 18b (FIG. 7). The convolutions 20 at this stage are being continually enlarged by virtue of the angular shifting of the ends. Hence, the convolutions have become larger in a transverse direction than in FIG. thus, the convolutions have been designated by the reference numeral a in FIG. 5 and their larger configuration as 20b in FIG. 7.

Continued advancement of a particular connector 14 will result in the ends thereof being brought into virtual longitudinal alignment. This condition is reached in the region represented by FIG. 8, the ends having been designated by the reference numerals 16c and 18c in FIG. 9 and the convolutions in their enlarged or expanded state by the reference numeral 20c.

It is when the convolutions assume the state represented in FIG. 9, although the transverse enlargement would be difficult to accurately portray in the drawing, the connector 1 4 is in readiness for the insertion or reception of the wires or rods 10, 12. The wires or rods 10, 12 are shown in FIG. 1 as having been so received within the enlarged convolutions of the foremost connector 14. It will perhaps be of help to explain that the legend opening tool applied to FIG. 1 represents the distance between the plane 44 of FIG. 3 and the end 26-.

Further advancement, which results in the expulsion of the foremost connector 14, causes its forward end 16 to leave the groove 30, more specifically the narrow end 3% thereof, with the consequence that the end 1 6 is free to snap or rotate back toward its original position with respect to the end 18 as illustrated in FIG. 2. It will be appreciated that the end 18 will still reside in the groove adjacent its narrow end 30b when the end 16 is released. Since the wires or rods 10 and 12 are within the enlarged convolutions 200, the convolutions which have been expanded by the foregoing cam action contract and thereby grip the elements 10 and 12. However, the ends 16 and 18 cannot resume their original or unflexed relationship. Instead, they are held in an intermediate position between that appear in FIG. 2 and that in which they appear in FIG. 9. To pictorially show this relationship, FIG. 10 has been presented and it will be noted that the ends 16 and 18 have been designated as 16d and 18d in this particular figure, the contracted convolutions being indicated by the reference numeral 20d.

Due to the gripping and retention of the connector 14 on the elements 10 and 12 as illustrated in FIG. 10, the gun 22 need only be manually withdrawn (assuming the wires or rods 10, 12 are stationary) with respect to the elements 10 and 12, the particular connector 14 then being pulled from the end of the barrel 24. The squeezing of the trigger 56 of the device will then advance the next succeeding connector 14 into a position so that additional wires or rods 10, 12 can be received and the action repeated continuously with respect to any number of pairs of elements 10 or 12 to be fastened together.

Of course, when the supply of connectors 14 within the barrel 24 has been exhausted, the ratchet bar 42 is again withdrawn by pressing down the pin or knob 66 so as to release the pawl 48 from the last notch 46 at the right so as to allow extraction of the bar 42. In this way, a new supply of helical spring connectors 14 may be placed within the barrel 22. It will be recognized that the connectors 14 need not be individualy inserted, for they may be suitably adhered to each other in a columnar relation so that the operator can always insert the proper number for the particular capacity of the device or gun 22 and do so more quickly than on an individual basis.

Whereas the embodiment just described makes use of a single groove 30, it is within the contemplation of the invention to use a pair of grooves, one being formed helically with respect to the other. The particular helical spring connector that is designed for this type of arrangement has been pictured in FIG. 11, having been indicated generally by the reference numeral 114. The tangentially projecting ends have been labeled 11-6 and 118, and the intermediate resilient convolutions by the reference numeral 120. It perhaps will facilitate an understanding of the modification now being described if it will be recognized that insofar as possible the magnitude of the reference numerals used in conjunction with FIGS. 19 have been increased by the value of Thus, the connector 14 of FIG. 2 corresponds functionally to the connector 114 of FIG. 11.

The modified barrel has been given the reference numeral 124 and has its fiat end 126. The bore or passage 128 extends through the fragmentarily depicted barrel 124. Instead of a single groove 30, however, the present embodiment makes use of two grooves 130 and 131. It is the groove 130 that traverses a helical route through the barrel 124, the groove 131 being straight. While each groove 130, 131 has two sides, only one side of each groove is really used as a camming surface. Thus, the particular side of the groove 130 has been assigned the reference numeral 132 and the camming surface provided by the groove 131 has its side designated as 134.

It is not believed necessary to describe the grooves in any great detail as basically the side progressions 132a, 13% and 1320 (FIGS. 13, 15 and 17) corresponding to 32a, 32b and 320 (FIGS. 4, 6 and 8, respectively) and 134a, 1341; and 134c (FIGS. 13, 15 and 17) correspond to 34a, 34b and 34c (FIGS. 4, 6 and 8, respectively).

It will be appreciated, though, that the forward end 116 is inserted in the groove 130 and the rear or trailing end 118 extends into the groove 131. Hence, when the foremost connector 114 reaches the region represented by FIG. 13, then the end 116 begins to be flexed from its normal relationship with the end 118 as presented in FIG. 11. Owing to the slight flexing at this stage, the ends have been indicated by the reference numerals 116a and 118a in FIG. 14.

Further advancement of the foremost connector 114 results in the end 116 being angularly shifted through approximately 90 and has been labeled 116b in FIG. 16. It is the surface 132 (specifically designated as 132b) that does the camming of this end, the surface 134 (specifically designated as 1341;) reactively acting against the end 118. Hence, the ends 116b and 118b represent an enlarged condition of the convolutions and the enlarged or expanded convolutions have been distinguished by the reference numeral 12012 in 'FIG. 16.

FIG. 17 represents the full flexing or angular shifting of the ends 116, 118 with respect to each other and in FIG. 18 the ends have been given the reference designations 1160 and 1180. The enlarged convolutions have been assigned the reference numeral 1200 in FIG. 18. It is when the foremost connector 114 reaches the region of the barrel 124 indicated by FIG. 17, the connector at this stage being shown in FIG. 18, that the wires or rods 10, 12 are inserted in the same fashion as they are shown in FIG. 1. Further advancement of the particular connector 114 will result in its forward end 116 being dislodged from the groove 130 with the consequence that this end snaps into the position appearing in the FIG. 19 to grip the inserted wires or connectors 10 and 12.

This completes the application of one connector 114 to a pair of wires or rods 10 and 12. The action is repeated for subsequent wires or rods 10, 12 in the same manner as was described in conjunction with the embodiment utilized in FIGS. 1-9.

I claim:

1. A device for applying a helical spring connector to a plurality of wire or rod elements, said connector having longitudinally spaced ends and a series of intermediate resilient convolutions, the device comprising a member having a passage extending therethrough for receiving the connector at one end and expelling the connector at its other end, and means within said passage for angularly shifting said connector ends with respect to each other as said connector is advanced from said one end of the passage to its said other end to transversely enlarge said convolutions for the accommodation therein of the plurality of elements to be gripped, whereby contraction of said convolutions effect the gripping of said elements.

2. A device in accordance with claim 1 in which said means includes a cam against which the forward end of the connector bears to produce said angular shifting.

3. A device in accordance with claim 2 in which said cam constitutes one side of a groove, the forward end of said connector projecting outwardly from said convolutions into said groove.

4. A device in accordance with claim 3 in which said means additionally includes a cam against which the rear end of the connector bears to constrain said rear end during said angular shifting.

5. A device in accordance with claim 4 in which said last-mentioned cam also constitutes a side of a groove.

6. A device in accordance with claim 5 in which said first and second sides are the opposite sides of the same groove and both of said connector ends project outwardly thereinto, said groove being wider at said one end of the passage than at its said other end.

7. A device in accordance with claim 6 in which said groove is coextensive with the length of said passage and said member is formed with a generally flat surface at said other end of said passage residing in plane substantially normal to the longitudinal axis of said passage against which the forward end of said connector moves after leaving said groove, the release of said forward connector end allowing said convolutions contract to grip said elements.

8. A device in accordance with claim 5 in which said second slide is a side of a second groove, the rear end of said connector projecting into said second groove and said grooves having an angular relationship.

9. A device in accordance with claim 8 in which said grooves are coextensive with the length of said passage and said member is formed with a generally flat surface at said other end of said passage residing in a plane substantially normal to the longitudianl axis of said passage against which the forward end of said connector moves after leaving its said groove, the release of said forward connector end allowing said convolutions to contract to grip said elements.

10. A device for applying helical spring connectors successively to different pairs of wire or rod elements, each connector having longitudinally spaced, outwardly extending ends and a series of intermediae resilient convolutions, the device comprising a tubular barrel having a generally cylindrical bore extending therethrough and groove means extending outwardly from said bore into which said connector ends project, and means for feeding said coil spring connectors through said bore, said groove means camming said connector ends relative to each other to transversely enlarge said convolutions for the reception of a pair of said elements, whereby sufiicient advancement of the foremost connector will cause its forward end to move out of said groove means at the end of said barrel remote from said feeding means with the consequence that said enlarged convolutions contract to grip the elements received therein.

11. A device in accordance with claim 10 in which said groove means constitutes a single groove, both of said connector ends extending tangentially with respect to said convolutions into said groove and said groove having a width nearer said feeding means sufficient to receive said connector ends and narrowing at said remote end of said barrel, the sides of said groove providing said camming.

12. A device in accordance with claim 10 in which said groove means constitutes a pair of grooves, one of said connector ends extending tangentially with respect to said convolutions into one of said pair of grooves and the other of said connector ends extending tangentially into the other of said grooves, one of said grooves progressing helically with respect to the other, one side of said groove and one side of said other groove providing said camming.

References Cited UNITED STATES PATENTS 3,200,488 8/1965 Johansson 29-212X 3,393,895 7/1968 Surletta et al. 29227X 3,461,536 8/1969 Skold 292l2 THOMAS H. EAGER, Primary Examiner US. Cl. X.R. 29-227 

